[RFC PATCH 22/40] target/arm: Hoist feature and dtb_compatible from KVM, HVF

[Richard Henderson <richard.henderson@linaro.org>]

These settings are generic and identical between the two
host accelerators.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/cpu64.c   | 23 ++++++++++++++++++++++-
 target/arm/hvf/hvf.c | 13 +------------
 target/arm/kvm.c     | 29 ++---------------------------
 3 files changed, 25 insertions(+), 40 deletions(-)

diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index 668e979a24..75a88f9deb 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -1090,6 +1090,21 @@ static void aarch64_neoverse_n1_class_init(ARMCPUClass *cpu)
     cpu->isar.reset_pmcr_el0 = 0x410c3000;
 }
 
+static void aarch64_host_class_init(ARMCPUClass *acc)
+{
+    /*
+     * While we don't know all the host details, we can assume at
+     * least v8 with VFPv4+Neon; this in turn implies most of the
+     * other feature bits.
+     */
+    acc->dtb_compatible = "arm,arm-v8";
+    set_class_feature(acc, ARM_FEATURE_V8);
+    set_class_feature(acc, ARM_FEATURE_NEON);
+    set_class_feature(acc, ARM_FEATURE_GENERIC_TIMER);
+    set_class_feature(acc, ARM_FEATURE_AARCH64);
+    set_class_feature(acc, ARM_FEATURE_PMU);
+}
+
 static void aarch64_host_object_init(Object *obj)
 {
 #if defined(CONFIG_KVM)
@@ -1122,8 +1137,12 @@ static bool aarch64_max_class_late_init(ARMCPUClass *cpu, Error **errp)
         return true;
     }
 
-    /* '-cpu max' for TCG: we currently do this as "A57 with extra things" */
+    /*
+     * '-cpu max' for TCG: we currently do this as "A57 with extra things"
+     * Retain the more generic dtb_compatible setting from host_class_init.
+     */
     aarch64_a57_class_init(cpu);
+    cpu->dtb_compatible = "arm,arm-v8";
 
     /*
      * Reset MIDR so the guest doesn't mistake our 'max' CPU type for a real
@@ -1316,10 +1335,12 @@ static const ARMCPUInfo aarch64_cpus[] = {
       .class_init = aarch64_a64fx_class_init,
       .object_init = aarch64_a64fx_object_init },
     { .name = "max",
+      .class_init = aarch64_host_class_init,
       .class_late_init = aarch64_max_class_late_init,
       .object_init = aarch64_max_object_init },
 #if defined(CONFIG_KVM) || defined(CONFIG_HVF)
     { .name = "host",
+      .class_init = aarch64_host_class_init,
       .object_init = aarch64_host_object_init },
 #endif
 };
diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
index 278a4b2ede..8bb8b475cd 100644
--- a/target/arm/hvf/hvf.c
+++ b/target/arm/hvf/hvf.c
@@ -97,10 +97,8 @@ static HVFVTimer vtimer;
 
 typedef struct ARMHostCPUFeatures {
     ARMISARegisters isar;
-    uint64_t features;
     uint64_t midr;
     uint32_t reset_sctlr;
-    const char *dtb_compatible;
 } ARMHostCPUFeatures;
 
 static ARMHostCPUFeatures arm_host_cpu_features;
@@ -489,13 +487,6 @@ static bool hvf_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
     hv_vcpu_exit_t *exit;
     int i;
 
-    ahcf->dtb_compatible = "arm,arm-v8";
-    ahcf->features = (1ULL << ARM_FEATURE_V8) |
-                     (1ULL << ARM_FEATURE_NEON) |
-                     (1ULL << ARM_FEATURE_AARCH64) |
-                     (1ULL << ARM_FEATURE_PMU) |
-                     (1ULL << ARM_FEATURE_GENERIC_TIMER);
-
     /* We set up a small vcpu to extract host registers */
 
     if (hv_vcpu_create(&fd, &exit, NULL) != HV_SUCCESS) {
@@ -532,7 +523,7 @@ static bool hvf_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
 
 void hvf_arm_set_cpu_features_from_host(ARMCPU *cpu)
 {
-    if (!arm_host_cpu_features.dtb_compatible) {
+    if (!arm_host_cpu_features.reset_sctlr) {
         if (!hvf_enabled() ||
             !hvf_arm_get_host_cpu_features(&arm_host_cpu_features)) {
             /*
@@ -544,9 +535,7 @@ void hvf_arm_set_cpu_features_from_host(ARMCPU *cpu)
         }
     }
 
-    cpu->dtb_compatible = arm_host_cpu_features.dtb_compatible;
     cpu->isar = arm_host_cpu_features.isar;
-    cpu->env.features = arm_host_cpu_features.features;
     cpu->midr = arm_host_cpu_features.midr;
     cpu->reset_sctlr = arm_host_cpu_features.reset_sctlr;
 }
diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index 02a15c6013..ac164a6130 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -50,9 +50,7 @@ static bool cap_has_inject_ext_dabt;
  */
 typedef struct ARMHostCPUFeatures {
     ARMISARegisters isar;
-    uint64_t features;
     uint32_t target;
-    const char *dtb_compatible;
 } ARMHostCPUFeatures;
 
 static ARMHostCPUFeatures arm_host_cpu_features;
@@ -1567,7 +1565,6 @@ static bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
     int fdarray[3];
     bool sve_supported;
     bool pmu_supported = false;
-    uint64_t features = 0;
     int err;
 
     /* Old kernels may not know about the PREFERRED_TARGET ioctl: however
@@ -1615,7 +1612,6 @@ static bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
     }
 
     ahcf->target = init.target;
-    ahcf->dtb_compatible = "arm,arm-v8";
 
     err = read_sys_reg64(fdarray[2], &ahcf->isar.id_aa64pfr0,
                          ARM64_SYS_REG(3, 0, 0, 4, 0));
@@ -1760,31 +1756,12 @@ static bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
 
     kvm_arm_destroy_scratch_host_vcpu(fdarray);
 
-    if (err < 0) {
-        return false;
-    }
-
-    /*
-     * We can assume any KVM supporting CPU is at least a v8
-     * with VFPv4+Neon; this in turn implies most of the other
-     * feature bits.
-     */
-    features |= 1ULL << ARM_FEATURE_V8;
-    features |= 1ULL << ARM_FEATURE_NEON;
-    features |= 1ULL << ARM_FEATURE_AARCH64;
-    features |= 1ULL << ARM_FEATURE_PMU;
-    features |= 1ULL << ARM_FEATURE_GENERIC_TIMER;
-
-    ahcf->features = features;
-
-    return true;
+    return !err;
 }
 
 void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu)
 {
-    CPUARMState *env = &cpu->env;
-
-    if (!arm_host_cpu_features.dtb_compatible) {
+    if (!arm_host_cpu_features.isar.id_aa64pfr0) {
         if (!kvm_enabled() ||
             !kvm_arm_get_host_cpu_features(&arm_host_cpu_features)) {
             /* We can't report this error yet, so flag that we need to
@@ -1797,9 +1774,7 @@ void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu)
     }
 
     cpu->kvm_target = arm_host_cpu_features.target;
-    cpu->dtb_compatible = arm_host_cpu_features.dtb_compatible;
     cpu->isar = arm_host_cpu_features.isar;
-    env->features = arm_host_cpu_features.features;
 }
 
 /**
-- 
2.34.1